1. Field of the Invention
The present invention relates to a screw positioning device for a screwdriver, and more particularly to a screw positioning device for a screwdriver that can be assembled and disassembled easily.
2. Description of the Prior Art
An automatic screw driving device is always provided with a connecting tube for connecting a screwdriver head to the screwdriving device, and this connecting tube normally has a screw positioning device for attracting and holding the screw to be driven. With reference to FIG. 1, a conventional screwdriver head connecting tube disclosed by TW Patent No. 94,103,623 is shown and comprises a connecting rod 11, a slide sleeve 12, a spring 13, a retaining ring 14 and a magnetic member 15. The connecting rod 11 is defined with a socket at either end thereof for insertion of the inserting rod 111 and a screwdriver head 112. The slide sleeve 12 is slidably mounted on the connecting rod 11. The spring 13 is installed on the connecting rod 11 and biased between the shoulder of the connecting rod 11 and the slide sleeve 12. The retaining ring 14 is installed on the connecting rod 11. The magnetic member 15 is fixed at an end of the slide sleeve 12 for retaining the fasteners (such as screw) to the screwdriver head 112 and has a hole for passage of the screwdriver head 112.
However, this conventional connecting tube still has the following shortcomings:
Firstly, the structure of the connecting tube is too complicated and its cost is high.
Secondly, the magnetic device for holding the screw of this conventional connecting tube only can be used on such a tool that comprises the inserting rod 111 and the rod 11, so it is too limited in applicability.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the screw positioning device for a screwdriver.